(107 days)
Fixation of fracture, fusion of a joint or bone reconstruction (osteotomy) of the phalanges, metacarpals and carpals of the hand.
The Twist off Screw is made of titanium alloy and consists of a screw integrated with separates from the screw when the head meets cortical bone. It is 2.0mm in diameter and 11 to 14mm in length and has a selftapping tip.
This document describes the safety and effectiveness of the Medinov-AMP Twist-off™ Screw (K971069).
1. Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Maximum torque at rupture for separation of holder and screw | Averages 0.17 Nm |
| Maximum torque at rupture of the Twist-off™ Screw | Averages 0.37 Nm |
Note: The document does not explicitly state "acceptance criteria" through specific threshold values or ranges. Instead, it reports the average performance values obtained from testing. The implication is that these reported values were deemed acceptable for market clearance.
2. Sample Size and Data Provenance
- Test Set Sample Size: Not explicitly stated in the provided text, only "Testing of the Twist-off Screw was performed for the K962233." This indicates that tests were conducted, but the number of screw units tested is not specified.
- Data Provenance: Not specified. The manufacturer (Medinov-AMP) is located in Roanne, France, but the location where the testing was performed is not mentioned. The data is retrospective as the testing was completed prior to the 510(k) submission.
3. Number of Experts and Qualifications for Ground Truth
Not applicable. The ground truth for this device's performance relies on physical testing of mechanical properties (torque at rupture), not on expert opinion or interpretation of images/data.
4. Adjudication Method for Test Set
Not applicable. Adjudication methods (like 2+1, 3+1) are typically used for establishing ground truth in studies involving subjective interpretation (e.g., image reading by multiple experts). The testing performed here involved objective mechanical measurements.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, an MRMC comparative effectiveness study was not done. This type of study is relevant for evaluating diagnostic tools where human readers interpret images or data, and the device aims to assist or replace human performance. The Twist-off™ Screw is a physical implant, not a diagnostic or AI-driven device.
6. Standalone Performance Study
Yes, a standalone study was performed in the sense that the mechanical properties of the device (torque at rupture) were tested independently. The reported values (0.17 Nm and 0.37 Nm) are the standalone performance of the screw under specific test conditions. This is a direct measurement of the device's physical capabilities, not an algorithm's performance.
7. Type of Ground Truth Used
The ground truth used was physical mechanical measurement. Specifically, the torque required to induce rupture, both for the separation of the holder and for the screw itself, was directly measured during testing.
8. Sample Size for the Training Set
Not applicable. This device is a mechanical implant, not an AI/ML algorithm that requires a training set.
9. How Ground Truth for the Training Set was Established
Not applicable, as there is no training set for a mechanical implant device.
§ 888.3040 Smooth or threaded metallic bone fixation fastener.
(a)
Identification. A smooth or threaded metallic bone fixation fastener is a device intended to be implanted that consists of a stiff wire segment or rod made of alloys, such as cobalt-chromium-molybdenum and stainless steel, and that may be smooth on the outside, fully or partially threaded, straight or U-shaped; and may be either blunt pointed, sharp pointed, or have a formed, slotted head on the end. It may be used for fixation of bone fractures, for bone reconstructions, as a guide pin for insertion of other implants, or it may be implanted through the skin so that a pulling force (traction) may be applied to the skeletal system.(b)
Classification. Class II.